Blocking device for ventilator

ABSTRACT

A blocking device coupled to a ventilator comprising: a frame extending from an air discharge port of a ventilator case having a fan which is rotated by a motor to suction inside air; an air passage formed by the frame to discharge the inside air to the outside therethrough; and a blocking plate mounted on a central shaft movably installed at the center of the frame. The blocking plate allows the inside air to be discharged when the blocking plate is pushed backward by the pressure of discharged air. When the fan does not rotate, the blocking plate and a blocking bump protruding from the inner surface of the frame are engaged with each other to block the air passage to prevent inner heat from being discharged and external air from being introduced.

BACKGROUND

The present invention relates to a blocking device coupled to a ventilator and, more particularly, to a blocking device for a ventilator, in which a frame is mounted to be extended from the air discharge port of a ventilator case, which is provided with a fan for rotating by a motor so as to suck inside air, such that an air passage, through which the inside air is discharged to the outside, is formed by the frame and a blocking plate is mounted on a center shaft, which is movably mounted in the center of the frame, and allows the inside air to be discharged while being pushed backward by the pressure of the air to be discharged, the blocking plate being engaged with a blocking bump protruding from the inner surface of the frame so as to seal the air passage when the fan does not rotate, thereby preventing the leakage of internal heat and the inflow of external air.

In general, a ventilator is installed in a hole in a wall or a window, and a fan is rotated using a motor so as to discharge inside air to the outside.

Such a ventilator has the disadvantages that the cold air, dust, noise, smell and the like are introduced to the inside of a building through the ventilator hole and the internal heat of the building escapes out while the ventilator is not in operation.

Meanwhile, in the apartment, the ventilation holes of bathrooms and kitchens are all connected to those of upper and lower floors such that odor, tobacco smoke, food odor, various parasitic harmful bacteria and the like spread to the upper and lower floors, thereby causing discomfort in life.

In order to solve the above-mentioned problems, Korean registered patent No. 10-1182542 discloses a blocking device for a ventilator, in which the wind to be discharged through the ventilator is allowed to be smoothly discharged to the outside and the discharge passage of the ventilator is sealed when the ventilator is not in use so as to prevent the loss of internal heat of the ventilator and the backflow of the external air. In addition, Korean registered patent No. 10-1188851 discloses a backflow prevention damper for a ventilator, which is installed between a duct and the discharge port of the ventilator so as to prevent the backflow of air, and Korean registered patent No. 10-0954259 discloses a power damper integrated ventilator for preventing the backflow of external harmful gas.

However, the conventional damper type blocking devices still have disadvantages that a damper plate is made of a thin resin plate and thus is vulnerable to thermal insulation so that the advantages of the damper can hardly be seen in cold regions.

In addition, conventional dampers cannot guarantee complete airtightness. Therefore, in China, where smog is heavy, there is a problem that even if the damper is used, it is impossible to completely block the smog flying into houses so that the exposure to the danger of smog cannot be prevented even indoors.

PRIOR ART DOCUMENTS

(Patent Document 1) KR 10-1182542 (6 Sep. 2012)

(Patent Document 2) KR 10-1188851 (28 Sep. 2012)

(Patent Document 3) KR 10-0954259 (14 Apr. 2010)

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made in an effort to solve the above-mentioned problems occurring in the prior arts, and it is an objective of the present invention to provide a blocking device for a ventilator, in which a frame is mounted to be extended from the air discharge port of a ventilator case, which is provided with a fan for rotating by a motor so as to suck inside air, such that an air passage, through which the inside air is discharged to the outside, is formed by the frame, and a blocking plate is mounted on a center shaft and allows the inside air to be discharged while being pushed backward by the pressure of the air so as to move away from a blocking bump, the blocking plate mounted on the center shaft being engaged with the blocking bump protruding from the inner surface of the frame so as to seal the air passage when the fan does not rotate, thereby preventing the leakage of internal heat and the inflow of external air.

In addition, the present invention has another objective to provide a blocking device for a ventilator, in which a blocking plate and a blocking bump are separated from each other so as to discharge air by the operation of a fan that rotates to discharge air, and the blocking plate and the blocking bump automatically come into contact with each other so as to block external air when the rotation of the fan is stopped.

Furthermore, the present invention has still another objective to provide a blocking device for a ventilator, in which a blocking plate for moving by the operation of a fan and a fixed blocking bump are made of a lightweight and thermal insulating material and come into surface contact with each other so as to completely block the flow of air when the fan is not in operation, thereby providing highly efficient thermal insulation and complete airtightness performance.

Moreover, the present invention has yet another objective to provide a blocking device for a ventilator, in which a frame is formed in multiple stages such that an air passage is blocked in multiple stages by a blocking bump and a blocking plate in each subsidiary frame and a hot wire is respectively installed in the blocking bump that comes into surface contact with the blocking plate and the inner surface of a bearing that comes into contact with a shaft and is stepwise driven to operate, thereby ensuring the airtightness of the air passage in a heavy smog region or a cold province and solving the malfunction problems caused by freezing.

According to the present invention to achieve the above objectives, in a blocking device for a ventilator, which is installed in a ventilator case 10 having a fan 12 for rotating by a motor 11 and sucking inside air, so as to block external air, there is provided the blocking device 100 for a ventilator, comprising a frame 110 mounted to be extended from an air discharge port 13, through which air is discharged, in the ventilator case 10 and fixed to an inner wall so as to form an air passage 111, through which the inside air is discharged to the outside, a blocking bump 120 made of a Styrofoam or Isopink material and protruding from the inner surface of the frame 110, a hollow center shaft 130 movably installed in the center of the frame 110, a blocking plate 140 made of a Styrofoam or Isopink material, formed in a shape corresponding to that of the blocking bump 120, and fixed to the center shaft 130 so as to come into surface contact with an inclination with the blocking bump 120 by the movement of the center shaft 130 and thus block the air passage 111, and a spring 160 provided around the center shaft 130.

In addition, the present invention further includes a bearing 150, through which the center shaft 130 is inserted, the frame 110, the blocking bump 120, the center shaft 130, the blocking plate 140 and the bearing 150 are formed in multiple stages, the coupling part 112 of the frame 110 has a fixing member, and the upper and lower ends of the center shaft 130 are coupled by means of bolts.

The frame 110 includes a basic frame 110 a provided at the upper end thereof and a subsidiary frame 110 b provided at the lower portion thereof, the blocking bump 120 includes a basic blocking bump 120 a provided at the upper end thereof and a subsidiary blocking bump 120 b provided at the lower portion thereof, the center shaft 130 includes a basic center shaft 130 a provided at the upper end thereof and a subsidiary center shaft 130 b provided at the lower portion thereof, the blocking plate 140 includes a basic blocking plate 140 a provided at the upper end thereof and a subsidiary blocking plate 140 b provided at the lower portion thereof, the bearing 150 includes a basic bearing 150 a provided at the upper end thereof and a subsidiary bearing 150 b provided at the lower portion thereof, the basic bearing 150 a is extended vertically from the inside of the lower portion of the basic frame 110 a such that the basic center shaft 130 a is inserted through the basic bearing 150 a, a spring support protrusion 154 is perpendicularly connected to the basic bearing 150 a, a spring guide part 151 is perpendicularly connected to the spring support protrusion 154 and formed to be parallel to the basic bearing 150 a, fixing rods 152 are provided on the outer circumferential surface of the spring guide part 151, and through holes 153 are formed between the fixing rods 152 such that air passes therethrough.

The spring 160 according to the present invention is located outside the basic bearing 150 a, into which the basic center shaft 130 a is inserted.

The fixing rod 152 according to the present invention is formed in a streamlined shape 152 a so as to have a larger cross-sectional area in a direction in which air is discharged, and a hot wire is provided inside the lower surface of the subsidiary blocking bump 120 b of the subsidiary frame 110 b and the inner surface of the subsidiary bearing 150 b.

The basic center shaft 130 a of the basic frame 110 a according to the present invention has a folded surface 131 formed integrally with the basic center shaft 130 a so as to fix the upper portion of the spring 160 fitted around the basic center shaft 130 a of the basic frame 110 a and the center shaft 130 is enabled to move to a predetermined width until the folded surface 131 comes into contact with the top head of the basic bearing 150 a when the center shaft 130 moves.

According to the present invention, the blocking plate 140 and the blocking bump 120 are made of the same material.

Advantageous Effects

The blocking device for a ventilator according to the present invention has the advantages that a frame is mounted to be extended from the air discharge port of a ventilator case, which is provided with a fan for rotating by a motor so as to suck inside air, such that an air passage is formed by the frame, and a blocking plate is mounted on a center shaft and allows the inside air to be discharged while being pushed backward by the pressure of the air to be discharged, the blocking plate mounted on the center shaft being engaged with the blocking bump protruding from the inner surface of the frame so as to seal the air passage when the fan does not rotate, thereby preventing the leakage of internal heat and the inflow of polluted external air (smog, fine dust or the like).

In addition, according to the present invention, the blocking plate and the blocking bump are automatically engaged or separated by the operation of the fan, so that no separate electrical or mechanical operation is required for airtightness.

Furthermore, according to the present invention, the blocking plate and the blocking bump are made of a material having a high thermal insulation property, thereby reliably preventing the release of internal heat.

In addition, according to the present invention, the blocking plate for blocking air and the blocking bump come into surface contact with each other such that it is possible to completely block the flow of air when the flow of air is not required.

Moreover, the blocking device for a ventilator according to the present invention has the advantages that the frame is formed in multiple stages such that the air passage is blocked in multiple stages by the blocking bump and the blocking plate in each frame and the hot wires are installed in the blocking bumps of the subsidiary frames and the bearings of the subsidiary frames and can be controlled to be stepwise driven to operate, thereby extremely reducing the loss of internal heat in a cold province and solving the malfunction problems caused by freezing.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view illustrating a state, in which a blocking bump and a blocking plate are engaged with each other such that an air passage is closed, according to an embodiment of the present invention,

FIG. 2 is a cross-sectional view illustrating a state, in which a blocking plate is separated from a blocking bump in response to the rotation of a fan such that an air passage is opened, according to an embodiment of the present invention,

FIG. 3(a) shows a basic frame and its bottom view according to an embodiment of the present invention,

FIG. 3(b) shows a subsidiary frame and its bottom view according to an embodiment of the present invention, and

FIG. 4 is a sectional view of a blocking device for a ventilator according to an embodiment of the present invention, in which each frame is separated.

BRIEF EXPLANATION OF REFERENCE SYMBOLS

 10: ventilator case  11: motor  12: fan  13: air discharge port 100: blocking device for a ventilator 110: frame 111: air passage 112: coupling part 113: projection 120: blocking bump 130: center shaft 131: folded surface 140: blocking plate 150: bearing 151: spring guide part 152: fixing rod 153: through hole 154: spring support protrusion 160: spring

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings for it to be readily carried out by a person skilled in the art.

As shown in FIG. 1 to FIG. 4, a blocking device 100 for a ventilator, according to the present invention, includes

a frame 110 mounted to be extended from an air discharge port 13, through which air is discharged, in the ventilator case 10, which has a fan 12 for rotating by a motor 11 and sucking inside air, and fixed to an inner wall so as to form an air passage 111, through which the inside air is discharged to the outside,

a blocking bump 120 protruding from the inner surface of the frame 110,

a center shaft 130 movably installed in the center of the frame 110,

a blocking plate 140 formed in a shape corresponding to that of the blocking bump 120, and fixed to the center shaft 130 so as to come into surface contact with the blocking bump 120 by the movement of the center shaft 130 and thus to block the air passage 111, and

a bearing 150 extended vertically from the inside of the lower portion of the frame 110 such that the center shaft 130 is inserted through the bearing 150, and having fixing rods 152 provided in a cross shape on the inner circumferential surface thereof and through holes 153 formed between the fixing rods 152 such that air passes therethrough.

The motor 11 and the fan 12 are installed at one side in the ventilator case 10 and an air discharge port 13 is formed at the opposite side such that as the motor 11 is driven and the fan 12 rotates to suck inside air, the air rotates inside the ventilator case 10 and is discharged through the air discharge port 13.

The frame 110 is mounted to be extended from the air discharge port 13 and is built in a wall so as to form the air passage 111, through which the inside of a building communicates with the outside, wherein the frame 110 is fixed in the wall by using urethane foam and the urethane foam is firmly fixed to a plurality of projections 113. In this case, in addition to the urethane foam, it is also possible to employ polyethylene PE foam, polystyrene PS foam, phenol T resin PF foam, polypropylene PP foam, urea resin UF foam, silicone PI foam, and melamine resin MF foam.

Meanwhile, the projections 113 reinforce the balance strength of the blocking bump 120 protruding from the inner surface of the frame 110, wherein it is preferable to provide such projections 113 on the frame 110 in such a manner that six projections are formed on a basic frame 110 a which is nearest to the air discharge port 13 and nine projections are formed on each of a first subsidiary frame 110 b-1 and a subsidiary frame 110 b-2 which are continuously disposed at the lower portion of the basic frame 110 a, but the number of the projections can vary depending on the length of the blocking bump.

The frame 110, the blocking bump 120, the center shaft 130, the blocking plate 140 and the bearing 150 are formed in multiple stages, wherein fixing member is provided to a coupling part 112 formed on the outer surface of the lower end of the frame 110 such that the basic frame 110 a, the first subsidiary frame, the subsidiary frame, . . . 110 b-1, 110 b-2, . . . , on which the fixing member are disposed continuously, are coupled to each other, thereby enabling the frame 110 to be used in multiple stages.

According to the present invention, each of the frame 110, the blocking bump 120, the center shaft 130, the blocking plate 140 and the bearing 150 is divided into a basic one provided at an upper portion and a subsidiary one provided at the lower end of the basic one, wherein each basic one is identified by a added to the end of the reference sign thereof and each subsidiary one is identified by b added to the end of the reference sign thereof.

In addition, as for the subsidiary ones, the upper one is further denoted by b-1 and the lower one is further denoted by b-2 in order.

The blocking bump 120 is formed to be protruded from the inner surface of the frame 110 and has a thickness to be gradually decreased toward the center portion.

The subsidiary frame 110 b has carbon film coating or a hot wire provided to the contact surfaces of the subsidiary blocking bump 120 b and the subsidiary blocking plate 140 b and the inner surface of the subsidiary bearing 150 b so as to cope with the freezing phenomenon.

The blocking bump 120 has an inclined shape with an area gradually decreasing from the center to the lower portion thereof and the lower surface of the blocking bump 120 comes into surface contact with the blocking plate 140 mounted on the center shaft 130 so as to be engaged with the blocking plate 140.

The blocking plate 140 is made of the same material as the blocking bump 120 and is formed in the shape of a pyramid such as a cone or a quadrangular pyramid or a pentagonal pyramid. When the fan 12 does not rotate, the blocking plate 140 is engaged with the lower surface of the blocking bump 120, thereby blocking the air passage 111. To the contrary, when the fan 12 rotates, the blocking plate 140 is pushed by the pressure of the air discharged through the air discharge port 13 and thus separated from the blocking bump 120, thereby opening the air passage 111.

In this case, it is preferable that the surfaces of the blocking bump 120 and the blocking plate 140 are engaged with each other at the angle of 45° so as to increase adhesion density and facilitate the separation therebetween. In addition, if the contact area between the blocking bump 120 and the blocking plate 140 is increased, it is possible to increase the thermal insulation and airtightness.

The blocking bump 120 and the blocking plate 140 are made of a lightweight insulating material having high thermal insulation property and thus may be made of a heat insulating material such as a bead method insulating material (EPS, Styrofoam) and a compression method insulating material (Isopink) but the heat insulating material is not limited thereto.

The center shaft 130 has a hollow shape and includes the basic center shaft 130 a, a first subsidiary center shaft 130 b-1, a subsidiary center shaft 130 b-2 and the like, which are continuously disposed and coupled to each other by bolts, wherein the subsidiary center shaft 130 b-1, 130 b-2 coupled at the lower portion has a screw (a bolt) formed on the outer circumferential surface of the upper end portion thereof such that the screw is inserted into the lower end of the center shaft 130 disposed at the upper portion and thus coupled thereto.

The basic center shaft 130 a is movably installed in the center of the basic frame 110 a by penetrating the center of the basic bearing 150 a that is mounted to be extended vertically from the lower end portion of the basic frame 110 a.

The basic bearing 150 a has a cylindrical hole formed to be penetrated by the basic center shaft 130 a as the basic center shaft 130 a is inserted into the same such that the basic center shaft 130 a can move inside the basic bearing 150 a.

A friction section is provided with high precision between the center shaft 130 and the bearing 150 so as to increase the lubricity of the center shaft 130 while minimizing the center deviation rate of the blocking plate relative to the blocking bump 120.

As shown in FIG. 3, the basic bearing 150 a has a cylindrical shape and provided in the center of the lower end of the base frame 110 a. The basic bearing 150 a has a spring support protrusion 154 and a spring guide part 151 formed on the outer circumferential surface at the lower portion, wherein the spring guide part 151 has the fixing rods 152 provided in a cross shape on the outer circumferential surface thereof and through holes 153 formed between the fixing rods 152 such that air passes therethrough.

Therefore, the bearing 150 is firmly fixed to the frame 110 by the fixing rods 152.

Meanwhile, a spring 160 is provided around the basic bearing 150 a, into which the basic center shaft 130 a is inserted, wherein a spring support protrusion 154 is formed to be concave by folding the outer circumferential surface of the basic bearing 150 a so as to fix the spring 160 and the spring support protrusion 154 is folded upward such that a spring guide part 151 is formed.

The spring support protrusion 154 has a shape corresponding to the lower end surface of the spring 160 and is fitted with the spring 160, thereby firmly supporting the lower end surface of the spring 160, which is compressed when the center shaft 130 moves. The spring guide part 151 is positioned in parallel to the basic bearing 150 a so as to prevent the spring from escaping at the outside of the spring 160.

The center shaft 130 has a folded surface 131 formed into a shape corresponding to the upper end surface of the spring 160, which is provided around the center shaft 130, so as to support the upper end surface of the spring 160, wherein the folded surface 131 is formed integrally with the basic center shaft 130 a so as to support the lower surface of the blocking plate 140. When the inside air is discharged, the center shaft 130 is pushed and thus presses the spring 160 provided around the center shaft 130 such that the spring 160 is allowed to move at uniform distances until the head part of the basic bearing 150 a reaches the folded surface 131.

The fixing rod 152 is formed in a streamlined shape 152 a so as to have a larger cross-sectional area in a direction in which air is discharged. As the center shaft 130 is pushed, the lower end surface comes into contact with the fixing rod 152 and the air escaping therethrough can be smoothly discharged without any large resistance by the protrusion parts 152 a.

Meanwhile, the frame 110 is fastened to an inner wall by using the urethane foam airtightly such that no air can move between the frame 110 and the inner wall, and the blocking bump 120 and the blocking plate 140 come into close contact with each other and are assembled together so as to prevent the flow of air when the fan 12 does not rotate.

In addition, the blocking plate 140 is firmly fixed to the center shaft 130 by the bolt and the nut, wherein a rubber packing is added between the bolt and the nut fitted with the center shaft so as to prevent the bolt and the nut from releasing unintentionally.

The spring 160 is provided with rubber latex coating so as to avoid rust from the exposure to moisture and is gradually decreased in width from the upper portion to the lower portion thereof so as not to come into contact with the spring guide part 151. In the subsidiary frame 110 b, the fixing rod 152 b is directly connected to the subsidiary bearing 150 b. The height of the subsidiary bearing 150 b coincides with the height of the fixing rod. On the center shaft 130 b of the subsidiary frame 110 b, the folded surface 131 b serves only as a supporting protrusion for the subsidiary blocking plate 140 b.

The hot wire is provided to the inside of the subsidiary bearing 150 b, that is, in the portion where the subsidiary bearing 150 b is in contact with the subsidiary center shaft 130 b. The hot wire operates in the same manner as the hot wire provided to the subsidiary blocking bump 120 b and functions to dissolve a condensed portion when the blocking plate 140 cannot move due to the condensation.

In the blocking device 100 for a ventilator as mentioned above, the blocking plate 140 fixed to the center shaft 130 is engaged with the blocking bump 120 and thus seals the air passage 111 when the fan 12 does not rotate. In addition, when the fan 12 rotates and thus the inside air is discharged through the air discharge port 13, the blocking plate 140 engaged with the blocking bump 120 is separated therefrom while the center shaft 130 is pushed by the pressure of the discharged air, and the spring 160 around the center shaft 130 and the bearing 150 is compressed such that the lower end surface of the blocking plate 140 comes into contact with the fixing rods 152, thereby allowing the inside air to escape through the through holes 153 of the bearing 150.

According to the blocking device 100 for a ventilator, the motor 11 is driven in response to power supply and thus the fan 12 rotates, opening the blocking plate 140. If the blocking plate 140 is not opened, a control means determines the generation of condensation resulted from the large difference of temperature between the inside and the outside and blocks the power supply for the motor 11 but allows the power supply for the hot wires incorporated in an outermost subsidiary blocking bump 120 b and an outermost subsidiary bearing 150 b of the subsidiary frame.

In the present invention, it is possible to provide one or more subsidiary blocking bumps 120 b and one or more subsidiary bearings 150 b. If a single subsidiary blocking bump 120 b and a single subsidiary bearing 150 b are provided, the hot wires of the subsidiary blocking bump and the subsidiary bearing are supplied with power and then the motor 11 is driven.

If a plurality of subsidiary blocking bumps and a plurality of subsidiary bearings are provided, the hot wires of the outermost subsidiary blocking bump and the outermost subsidiary bearing thereof are supplied with the power and then the motor 11 is supplied with power. If the blocking plate 140 is not opened even in this case, the condensation is dissolved by supplying power to the hot wires of the subsidiary blocking bumps and the subsidiary bearings gradually in the indoor direction from the outermost subsidiary blocking bump and the outermost subsidiary bearing to next ones adjacent to the outermost subsidiary blocking bump and the outermost subsidiary bearing.

In the blocking device for a ventilator according to the present invention described above, the subsidiary frame 110 b-1, 110 b-2, . . . has the carbon film coating or the hot wire provided to the subsidiary blocking bump 120 b and the subsidiary bearing 150 b and the control means for repetitive inspection, thereby dissolving the condensation between the subsidiary blocking plate 140 b and the subsidiary blocking bump 120 b and between the subsidiary center shaft 130 b and the subsidiary bearing 150 b.

Therefore, the blocking device 100 for a ventilator according to the present invention has the effect that the frame 110 is mounted to be extended from the air discharge port 13 of the ventilator case 10, which is provided with the fan 12 for rotating by the motor 11 so as to suck the inside air, such that the air passage 111 is formed by the frame 110, the center shaft 130 movably installed in the center of the frame 110 is moved by the pressure of the air to be discharged and thus allows the air to be discharged to the outside, and the blocking plate 140 mounted on the center shaft 130 is engaged with the blocking bump 120 protruding from the inner surface of the frame 110 so as to seal the air passage 111 when the fan 12 does not rotate, thereby preventing the leakage of internal heat and the inflow of polluted external air.

In addition, the blocking device 100 for a ventilator according to the present invention has the effect that the frame 110 is formed in multiple stages such that the air passage 111 is blocked in multiple stages by the blocking bump 120 and the blocking plate 140 in each frame 110 and the carbon film coating or the hot wires are provided to the lower surface of the subsidiary blocking bump 120 b of the subsidiary frame 110 b and the inner surface of the subsidiary bearing 150 b and can be controlled to be stepwise driven to operate, thereby ensuring the airtightness and thermal insulation of the air passage in a cold province, completely prevent the loss of internal heat, and solving the malfunction caused by the condensation.

In addition, the present invention has the effect of precisely ensuring the airtightness of the air passage, thereby blocking the fine inflow of smog. 

1. In a blocking device (100) for a ventilator, which is located at a position where the inside and the outside of a building are connected and installed in a ventilator case (10), which has a fan (12) for rotating by a motor (11) and sucking inside air, so as to block external air, the blocking device for a ventilator, comprising: a frame (110) mounted to be extended from an air discharge port (13), through which air is discharged, in the ventilator case (10) and fixed to an inner wall so as to form an air passage (111), through which the inside air is discharged to the outside; a blocking bump (120) made of an insulating material and protruding from the inner surface of the frame (110); a hollow center shaft (130) movably installed in the center of the frame (110); a blocking plate (140) made of an insulating material, formed in a shape corresponding to that of the blocking bump (120), and fixed to the center shaft (130) so as to come into surface contact with an inclination with the blocking bump (120) by the movement of the center shaft (130) and thus block the air passage (111), wherein a spring (160) is provided around the center shaft (130), a bearing (150) is provided such that the center shaft (130) is inserted through the bearing (150), the frame (110), the blocking bump (120), the center shaft (130), the blocking plate (140) and the bearing (150) are formed in multiple stages, the frame (110) includes a basic frame (110 a) provided at the upper end thereof and a subsidiary frame (110 b) provided at the lower portion thereof, the blocking bump (120) includes a basic blocking bump (120 a) provided at the upper end thereof and a subsidiary blocking bump (120 b) provided at the lower portion thereof, the center shaft (130) includes a basic center shaft (130 a) provided at the upper end thereof and a subsidiary center shaft (130 b) provided at the lower portion thereof, the blocking plate (140) includes a basic blocking plate (140 a) provided at the upper end thereof and a subsidiary blocking plate (140 b) provided at the lower portion thereof, the bearing (150) includes a basic bearing (150 a) provided at the upper end thereof and a subsidiary bearing (150 b) provided at the lower portion thereof, and the spring (160) is located outside the basic bearing (150 a), into which the basic center shaft (130 a) is inserted.
 2. The blocking device for a ventilator according to claim 1, wherein the basic bearing (150 a) is extended vertically from the inside of the lower portion of the basic frame (110 a) such that the basic center shaft (130 a) is inserted through the basic bearing (150 a), a spring support protrusion (154) is perpendicularly connected to the basic bearing (150 a), a spring guide part (151) is perpendicularly connected to the spring support protrusion (154) and formed to be parallel to the basic bearing (150 a), fixing rods (152) are provided on the outer circumferential surface of the spring guide part (151), and through holes (153) are formed between the fixing rods (152) such that air passes through the through holes (153).
 3. The blocking device for a ventilator according to claim 2, wherein the fixing rod (152) is formed in a streamlined shape (152 a) so as to have a larger cross-sectional area in a direction in which air is discharged, and a hot wire is provided inside the lower surface of the subsidiary blocking bump (120 b) of the subsidiary frame (110 b) and the inner surface of the subsidiary bearing (150 b).
 4. The blocking device for a ventilator according to claim 2, wherein a folded surface (131) is formed integrally with the basic center shaft (130 a) so as to fix the upper portion of the spring (160) fitted around the basic center shaft (130 a) of the basic frame (110 a) and the center shaft (130) is enabled to move to a predetermined width until the folded surface (131) comes into contact with the top head of the basic bearing (150 a) when the center shaft (130) moves.
 5. The blocking device for a ventilator according to claim 1, wherein the blocking plate (140) and the blocking bump (120) are made of the same material. 